Sixteen Experimental Investigations from the Harvard Psychological Laboratory | Page 2

relation to the motor functions, we have good reasons for turning to them, as the ?sthetic feelings are of all feeling processes decidedly those which can be produced in the laboratory most purely; their disinterested character makes them more satisfactory for experimental study than any other feelings.
Another group of researches which predominates in our laboratory is that on comparative psychology. Three rooms of the laboratory are reserved for psychological experiments on animals, under the special charge of Dr. Yerkes. The work is strictly psychological, not vivisectional; and it is our special purpose to bring animal psychology more in contact with those methods which have found their development in the laboratories for human psychology. The use of the reaction-time method for the study of the frog, as described in the fifteenth paper, may stand as a typical illustration of our aim.
All the work of this volume has been done by well-trained post-graduate students, and, above all, such advanced students were not only the experimenters but also the only subjects. It is the rule of the laboratory that everyone who carries on a special research has to be a subject in several other investigations. The reporting experimenters take the responsibility for the theoretical views which they express. While I have proposed the subjects and methods for all the investigations, and while I can take the responsibility for the experiments which were carried on under my daily supervision, I have left fullest freedom to the authors in the expression of their views. My own views and my own conclusions from the experiments would not seldom be in contradiction with theirs, as the authors are sometimes also in contradiction with one another; but while I, of course, have taken part in frequent discussions during the work, in the completed papers my r?le has been merely that of editor, and I have nowhere added further comments.
In this work of editing I am under great obligation to Dr. Holt, the assistant of the laboratory, for his helpful co?peration.
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CONTENTS.
Preface: Hugo Münsterberg ...................................... i
STUDIES IN PERCEPTION.
Eye-Movement and Central An?sthesia: Edwin B. Holt ........... 3 Tactual Illusions: Charles H. Rieber ......................... 47 Tactual Time Estimation: Knight Dunlap ....................... 101 Perception of Number through Touch: J. Franklin Messenger .... 123 The Subjective Horizon: Robert MacDougall .................... 145 The Illusion of Resolution-Stripes on the Color-Wheel: Edwin B. Holt .............................................. 167
STUDIES IN MEMORY.
Recall of Words, Objects and Movements: Harvey A. Peterson ... 207 Mutual Inhibition of Memory Images: Frederick Meakin ......... 235 Control of the Memory Image: Charles S. Moore ................ 277
STUDIES IN ?STHETIC PROCESSES.
The Structure of Simple Rhythm Forms: Robert MacDougall ...... 309 Rhythm and Rhyme: R.H. Stetson ............................... 413 Studies in Symmetry: Ethel D. Puffer ......................... 467 The ?sthetics of Unequal Division: Rosewell Parker Angier .... 541
STUDIES IN ANIMAL PSYCHOLOGY.
Habit Formation in the Crawfish, Camburus affinis: Robert M. Yerkes and Gurry E. Huggins ............................. 565 The Instincts, Habits and Reactions of the Frog: Robert Mearns Yerkes .............................................. 579
STUDIES IN PSYCHOLOGICAL THEORY.
The Position of Psychology in the System of Knowledge: Hugo Münsterberg ........................................... 641

PLATES.
OPPOSITE PAGE Plate I ....................................................... 20 " II ....................................................... 24 " III ....................................................... 28 " IV ....................................................... 34 " V ....................................................... 190 " VI ....................................................... 198 " VII ....................................................... 200 " VIII ....................................................... 314 " IX ....................................................... 417 " X ....................................................... 436
Charts of the Sciences, at end of volume.
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STUDIES IN PERCEPTION.

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EYE-MOVEMENT AND CENTRAL AN?STHESIA.
BY EDWIN B. HOLT.
I. THE PROBLEM OF AN?STHESIA DURING EYE-MOVEMENT.
A first suggestion of the possible presence of an?sthesia during eye-movement is given by a very simple observation. All near objects seen from a fairly rapidly moving car appear fused. No further suggestion of their various contour is distinguishable than blurred streaks of color arranged parallel, in a hazy stream which flows rapidly past toward the rear of the train. Whereas if the eye is kept constantly moving from object to object scarcely a suggestion of this blurred appearance can be detected. The phenomenon is striking, since, if the eye moves in the same direction as the train, it is certain that the images on the retina succeed one another even more rapidly than when the eye is at rest. A supposition which occurs to one at once as a possible explanation is that perchance during eye-movement the retinal stimulations do not affect consciousness.
On the other hand, if one fixates a fly which happens to be crawling across the window-pane and follows its movements continuously, the objects outside swim past as confusedly as ever, and the image of the fly remains always distinct. Here the eye is moving, and it may be rapidly, yet both the fly and the blurred landscape testify to a thorough awareness of the retinal stimulations. There seems to be no an?sthesia here. It may be, however, that the eye-movement